Method and apparatus for surface-treating continuously cast special steel slabs



Unite States Patent Inventors Appl. No. Filed Patented Assignees Priority METHOD AND APPARATUS FOR SURFACE- TREATING CONTINUOUSLY CAST SPECIAL STEEL SLABS 7 Claims, 7 Drawing Figs.

US. Cl 90/24.3 Int. Cl B23d 1/30 Field of Search 90/24.3,

Primary ExaminerGil Weidenfeld Attorneywenderoth, Lind and Ponack ABSTRACT: An apparatus for continuously surface treating cast special steel slabs. The apparatus has a forwardly and rearwardly movable table on which a continuously cast special steel slab can be mounted and supported. Means for providing a memory of the shape of the surface of the slab extend along the side parts of the top surface of the slab, and a cutter supporting crossrail is positioned above said table and extends transversely of the direction of movement of the table and is movable up and down relative to said table. Cutter means is provided on said crossrail, and means are provided for supporting said crossrail and are coupled to and actuated by said memory providing means for inclining said crossrail transversely of the table depending on the shape of the top surface of the slab at the edges thereof so that the position of the crossrail corresponds to the shape of the slab. The invention also includes the method of operating the apparatus for carrying out surface treating by the use of such an apparatus.

Patented Nov, 24, 1976 3,541,923

Sheet 1 of 3 PIC-M INVENTORS J KICHIRO SAIGO NAOKICHI MATSUI BY WW, zfwz ATTORNEYS Fammd Nam 24, L7 3,541,923

ZMM 22am ATTORNEYS atented Nov. 24, 1970 3,541,923

Sheet 3 of3 FIG.4

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1-: mit i4 INVENTORS KICHIRO SAIGO NAOKICHI MATSUI III BY //W/W%,%m M

ATTORNEYS METHOD AND APPARATUS FOR SURFACE-TREATING CONTINUOUSLY CAST SPECIAL STEEL SLABS This application is a continuation-in-part of application Ser. No. 509,956, filed Nov. 26, 1965, now abandoned.

This invention relates to a method and apparatus for surface-treating continuously cast special steel slabs.

Due to the recent development of continuous casting, such special steel plates as, for example, stainless steel plates are produced by the steps of making steel slabs from molten steelby continuous casting, treating the surface flaws of the slabs and then rolling the slabs. However, such continuously cast slabs generally have wrinkles and metallurgical hypodermic defects produced by' the rocking action used in the casting. If left as they are, they will remain as flaws after theslabs are rolled. Therefore, such wrinkles and defects must be removed. Further, it usually happens that any slab is curved or twisted over the entire length, has a different thickness in the middle than at the ends and is larger in the middle part between the edges or is in the form of a so called crown. There have been various difficulties in machining such slabs with a high yield so that no black skin remains on the. surface. Therefore, in general, the flaws on'th'e surface of such slab are treated and the black skin of the slab is removed 'by grinding. However,

such treatment of the flaws and treatment of the surface with a grinder is inefficient and has the drawback that chips of the special steel can not be recovered. Specifically, due to the quenching treatment during the continuous casting process, the slab has such a high crack-sensitivity that the surface of the slab is apt to be cracked by the grinder and there is a danger that the cracks will remain as surface defects even after the slab is rolled.

Therefore, an object of the present invention is to provide a method and apparatus for surface-treating or favorably machining special steel slabs obtained by continuous casting in response to the degrees of their curvatures and deformations in the longitudinal and lateral directions in order to eliminate such defects.

Another object of the present invention is to provide a method of surface-treating continuously cast special steel in which means providing a memory of the curvatures and deformations of a special steel slab obtained by continuous casting is provided and the slab is machined while following its curvatures and deformations by converting the deviations in the memory into power.

A further object of the present invention is to provide an apparatus for surface-treating continuously cast special steel slabs comprising a forward and rearward moving stand on which a slab can be mounted and supported, a means providing a memory of curvatures and deformations of the slab and a device for rocking a cutter rest or the forward and rearward moving stand while properly setting the relative positions of the cutter and slab in response to the memory in order to carry out the above described method.

In the present invention, the means for providing the memory of the curvatures and deformations of continuously cast special steel slabscan be a mechanical memory such as a templet or an electromagnetic memory means such as a magt netic tape or a photoelectric cell. When a mechanical memory means, such as a templet, is used the deviation of the curvatures and deformations'of the slab is mechanically converted to power. Further, thecurvatures and deformations of the slab can be artificially memorized in the templetil lowever, it is preferable to memorize them automatically so that the deformations of the material being cut while the surface of the slab is being skinned may be followed.

These objects are achieved by the apparatus of the present invention which has aforwardly and rearwardly movable table on which a continuously ca'st special steel slab can be mounted and supported. Means for providing a memory of the shape of the surface of the slab extend along the side parts of the top surface of the slab, and a cutter supporting crossrail is positioned above said table and extends transversely of the direction of movement of the table and is movable up and down relative to said table. Cutter means is provided on said crossrail, and means are provided for supporting said crossrail and are coupled to and actuated by said memory providing means for inclining said crossrail transversely of the table depending on the shape of the top surface of the slab at the edges thereof so that the position of the crossrail corresponds to the shape of the slab.

' This invention will now be explained with reference to the accompanying drawings, in which:

FIG. I is a side view of a planer according to the present invention;

FIG. 2 is a front view of the same;

FIG. 3 is a detailed front view of a cutter support of the apparatus of FIG. 1; I

FIG. 4 is a detailed rear view of the crossrail of the apparatus of FIG. 1;

FIG. 5 is a plan view of the crossrail of FIG. 4;

' FIG. 6 is a sectional view taken on line Vl-Vl of FIG. 4; and

FIG. 7 is a sectional view taken on line VII-VII of FIG. 4. The apparatus illustrated in FIGS. 1 and 2 is an automatical following planer which can carry out the method of the present invention and has a bed 3, a table 4 reciprocally movable in the longitudinal direction of said bed 3, gate-forming columns 5 on opposite sides of the bed 3 with a crosspiece 5a between the tops of of columns 5, a crossrail 7 supported so as to be slidable and rockable inthe vertical direction by a pair of oil pressure cylinders 6 on said crosspiece 5a, a face cutter support 8 supported on crossrail 7 so as to be movable in the lateral direction of said table and along said crossrail, and a side cutter support 9 fixed to one ofthe columns.

Said planer is the type in which the cutter support is fixed relative to the length of the table and the table is movable. Said table 4 can reciprocate in the longitudinal direction along the bed 3. A slab 10 to be cut is securely fixed on said table 4 by a plurality of jacks 11 and fixtures 12.

A templet 14 for controlling following action of the cutter as the slab moves lengthwise is provided on each side of the table 4 and is in the form of a relatively thin elongated member which can be bent so that the contour will conform to the'sh'ape of the slab 10 along the upper side edge of the slab when the slab is fixed on the table 4, the templet 14 being mounted in adjustable mounting means (not shown) by the adjustment of which the contour of the templet is adjusted. Said crossrail 7 which is hung and supported on the gateshaped columns 5 on the pair ofoil pressure cylinders 6 can be moved in the vertical direction along the columns 5 and also rocked by controlling the oil pressure in the respective cylinders 6 as will be explained in detail later. The control of oil pressure in the cylinders 6 causes'the crossrail 7 to perform a following motion so that it stays parallel to the transverse profile ofthe upper surface ofthe cross section ofthe slab. Oil pressure controlling devices 19 are provided on the back of the crossrail'and are operated from the templets 14 through arms 16 pivoted on frames 5 and each having a follower 17 for following the curvatures and deflections of the upper edge on each side-of the slab 10 so that the crossrail can be made to perform a parallel following motion always at a fixed distance from the upper surface of the cross section of the slab by the operation of the cylinders 6 by said oil pressure controlling device 19'. In addition, onthe back of the crossrail 7 are provided a following controlling device and respective oil pressure controlling devices for operating such devices as the face cutter support crossrail, and cutter carrying oil pressure cylinders.

As seen in FIG. 1, one end of each arm 16 engages the respective templet 14 through the follower 17,which can be a roller, and the other end engages a respective control needle 19 of a respective controlling device 19'. The arms 16 cause the control needles to move up and down according-to the profile of the templets 14, thereby operating the guiding valves 19 of the controlling devices 19' (FIG. 4).

The controlling devices 19 are so connected with the oil pressure cylinders 6 that oil is charged and discharged alternately; and said oil pressure cylinders '15 have the cylinders pivotally connected to the crossrail 7 and the pistons are fixed to the crosspiece a of the columns 5. Therefore, when the follower 17 on one arm 16 moves down from the position shown in FIG, 1, the corresponding feeling needle 19 is moved up, causing the guiding valve 19 to move up so as to fill the lower part of one oil pressure cylinder 6 with pressure oil through the oil distribution plate and to introduce the discharged oil from the upper part of the oil pressure cylinder through the oil distribution plate to the guiding valve 19''.

Thus, the cylinder part of the one oil pressure cylinder 6 goes down, moving the corresponding end of the crossrail 7 down.

On the contrary, when one follower 17 moves up, the corresponding guiding valve 19 goes down so as to fill the upper part of the one oil pressure cylinder 6 with pressure oil, whereby the cylinder part and then the corresponding end of the crossrail 7 move up. The oil pressure cylinders 6 are so devised that they move up and down slightly even with small movements of the guiding valves 19". i

It will thus be seen that these devices of the present invention make it possible for the crossrail to carry out a constant,

parallel profiling movement over the upper surface of the slab.

As illustrated in detail in FIG. 3, the face cutter support 8 which can be moved in the lateral direction by the operation ofa feed screw 18 is slidably supported on the crossrail 7. Said face cutter support 8 comprises a saddle 20 movable in the lateral direction along the guide surface of the crossrail 7 and a plurality of tool heads 21, 22, 23 and 2d movable vertically on said saddle 20. Cutters 25 and 26 to cut the upper surface of the slab are fixed to said tool heads.

The tool heads 21 and 24 on the opposite ends of the row of tool heads on the face cutter support 8 cut the inclined parts on both sides of the slab and have following devices 28 connected thereto for following templet 27 provided on the cross rail 7 and moving the tool heads vertically in accordance with the profile of the templets 27v The tool heads can be piston cylinder devices similar to devices 6, and following devices 28 can be devices similar to elements 19 and 19. Therefore, during the lateral movement of the cutter support 8, the tool heads 21 and 24 on the ends of the row will follow the respective templets 27 so as to perform following motions with respect to the cutter support 8 so that both side parts of the upper surface of the slab it) will be finished so as to be in con dition for rolling. The templets 27 are adjustable so that any required contour of the side parts of the upper surface of the slab can be cut. Further, both the tool heads 21 and 24 are provided with an adjusting handle 30 for moving the head vertically so that the initial position of the head with respect to the cutter support 8 can be adjusted.

Said tool heads 21, 22, 23 and 2d are securely clamped to the face cutter support 8 by means of several automatic clamping devices 33 in the case ofthe cutting stroke.

Further, the lateral feed of the cutters or the lateral movement of the face cutter support 8 is automatically carried out by the feeding screw 18.

As illustrated in FIGS. 4 and 5, the crossrail 7 is so formed as to beslidable and rockable in the vertical direction along the guide surface of the columns 5 under the control of the oil pressure cylinders 6. That is to say, the crossrail 7 supported from the pair of oil pressure cylinders 6 is provided at each end with a rockable rocking sliding metal piece 35 in contact with one side of the column 5 and a sliding metal piece 43 urged thereagainst by a spring 42, and is also provided with two sets of sliding metal pieces 45 and 46 urged into contact with the back surfaces of both columns by springs 48 so that the crossrail 7 can slide and rock along the columns 5 in response to the respective amounts of movement of the oil pressure cylinders 6. 1

Each rocking sliding metal piece 35 is pivoted to the crossrail 7 on a center pin 36 so as to be rotatable around said center pin 36. As illustrated in detail in- FIG. 6, said sliding metal piece 43 has an adjusting screw 41 with a head 37 fitted on a bracket 38 on the crossrail '7 and the sliding metal piece 43 is pressed against the guide surface of the column by the spring 42 which can be a dish spring provided near the forward end of said adjusting screw 41 so that the pressing force of the dish spring 42 can be adjusted by movement of the adjusting screw 41. Therefore, the force in the direction of the side surface of the crossrail 7 on the column will be received by said rocking sliding metal piece 35 and sliding metal piece 43 will slide along the crossrail 7 in the vertical direction along the column.

' Further, as illustrated in detail in FIGS. 6 and 7, the crossrail 7 is provided with two sets of sliding metal pieces 45 and 46 of the same structure. Each of said sliding metal pieces 45 and 46 has a screw 47 threaded into the crossrail, a dish spring 48 and a sliding plate 49 pressed against the guide surface of the column 5 by said dish spring 48 so that the pressing force of the dish spring 48 can be adjusted by screw 47. Therefore, the force in the direction of the front surface of the crossrail 7 on the column 5 will be received by said two sets of sliding metal pieces 45 and -36 and the crossrail 7 will be allowed to slide in the vertical direction along the column.

Because the rocking sliding metal piece 35 and sliding metal pieces 43, 45 and 46 are provided, the crossrail 7 will be able to slide and rock in the vertical direction along the column in response to the respective amounts of operation of the oil pressure cylinders 6 and therefore will beable to perform a following motion which is always parallel with the upper surface of the cross section of the slab in response to any deflections in the lengthwise direction and curvatures of the plane surface of the slab 10.

Further, as illustrated in FIGS, 1 and 2, a side cutter support 9 for cutting the side surface of the slab 10 is provided on the lower part of one column 5 of thegate-forming columns. Said side cutter support 9 is provided with an appropriate feeding device, such as a device like that used for cutters 25 and 26, so that the feed in the vertical and horizontal directions can be carried out with said feeding device.

The actual operation of the thus constructed automatic following planer of the present invention is as follows.

The special steel slab 10 to be skinned is placed substantially horizontally on the jacks 11 on the table 4 and is fixed on the table 4 with many fixtures 12 so that the side surface of the slab is parallel with the table. However, no fixture is fixed to the slab side surface on the side of the side cutter support 9 because it will be in the way of skinning of the side surface. Then, the slab 10 is skinned first on one side surface with the side cutter on support 9 in response to movement in the longitudinal direction of the table so that no black skin will remain on the table. When the skinning of one sidesurface of the slab with the side cutter on support 9 has been finished, the fixtures are fixed also to said side surface of the slab to fix the slab to the table more securely. The templets 14 along the length of the table 4 are adjusted so as to lie parallel to both upper side edges of the-slab. Then the table 4 is moved so that the forward end of the slab is under the crossrail 7. The crossrail is adjusted so as to be parallel with the top surface of the slab. At the same time, the followers 17 on the arms 16 are positioned against templets 14 and the feelers 19 will rest on v the other ends of arm 16. The cutters 26 for cutting the top surface parallel to the crossrail are fixed to the tool heads 22 and 23 so that the tips of the cutters are parallel with the crossrail. The cutter 25 for cutting the side part of the top surface of the slab'is fixed to each of the tool heads 21 and 24. The templet 27 for moving the cutter of each of said tool heads 21 and 24 is set and the tool heads 21 and 24 are adjusted.

When the adjustment of the device for following the contour of the slab has been finished and the preparation for skinning the upper surface of the slab has been completed, the table is moved in the lengthwise direction so that the skinning of the upper surface of the slab is carried out. The two heads 21 and 24 are moved transversely by the back and forth movement of the cutter support 8 between successive back and forth movements of the slab 10. Movement of the slab 10 by movement of the table 4 causes the crossrail 7 to be raised and lowered, depending upon the movement of the followers 17 moving along the templets 14. It should be understood that although the slab may be deposited so that one edge is lower than the other, this will simply cause the crossrail 7 to be tilted, one end being lifted higher than the other, so that the cutter support 8 will move in a direction parallel to the plane of the slab at the particular point along its length which is positioned beneath the cutters.

As can be seen from FIG. 3, the cross-sectional profile of the slab has a bulge at the center portion thereof, and is slightly tapered the edge parts. It is for this reason that the templets 27 are provided for causing the cutters in the ends of the row of cutters to move upwardly and downwardly so as to follow the general profile. The central cutters 26 are simply caused to follow the contour of the crossrail 7 along which the support slides so that the central portion of the slab is cut so as to be substantially flat. By the combination of these actions, the slab is properly skinned so as to remove the portion indicated in FIG. 3 by the dot-dash dash line. The slab can then be turned over and in the same manner as is described above, the other side surface and the lower surface of the slab 19 can be skinned.

Thus, according to the present invention, the slab surface can be skinned in response to the degrees of the curvatures and deformations in the longitudinal and lateral directions of the special steel slab obtained by continuous casting.

A comparison of actual slab treating capacities of a planer apparatus for carrying out the method of the present invention and a conventional grinder is shown in the following table wherein the treated slab was a stainless steel SUS 27 having a thickness of l 17 mm., a width of 1040 mm., and a length of 700 mm., and a weight of 6.6 tons.

Conventional grinder .7 0. Planer of the invention,.. 1.

Further, in grinding with the conventional grinder, the temperature of the slab rose to about 1000C., and cracks were produced on the surface of the slab. This did not occur with the apparatus of the present invention.

We claim:

1, A method of treating the surface of continuously cast slabs which comprises fixing a slab and supporting it for planing, providing a memory of the existing shape of the top surface of the slab along the two longitudinal edges of said slab, driving a cutter supporting crossrail according to the memory of the shape to move the respective ends of the crossrail up and down depending on the shape of the corresponding surface at the edge of the slab, and while thus moving the crossrail, producing successive reciprocal relative movements between the slab and the crossrail in the direction of the longitudinal edges of the slab and moving the cutters on the crossrail transversely of the slab in the desired transverse cross section of the slab between successive reciprocal movements.

2. An apparatus for continuously surface treating cast special steel slabs, comprising a forwardly and rearwardly movable table on which a continuously cast special steel slab can be mounted and supported, means for providing a memory of the existing shape of the surface of the slab along the side parts of the top surface of the slab, a cutter supporting crossrail above said table and extending transversely of the direction of movement of the table and movable up and down relative to said table, cutter means on said crossrail, and means supporting said crossrail and coupled to actuation means engaged with said memory providing means for inclining said crossrail transversely of the table depending on the shape of the top surface of the slab at the edges thereof so that the position of the crossrail corresponds to the top surface profile of the cross section of the slab.

3. An apparatus for continuously surface treating cast special steel slabs, comprising, in combination a table reciprocally movable in the longitudinal direction thereof, a frame over said table, a crossrail supported on said frame for slidable movement in the vertical direction along said frame and inclinable in a direction transversely of the table, a pair of crossrail moving means mounted on said frame and spaced transversely from each other along the frame and connected to said crossrail for moving said crossrail up and down along said frame and separately movable for inclining said crossrail in a direction transversely of the table, cutter means mounted on said crossrail for movement transversely of the table, means for driving said cutter means transversely of the table, an adjustable templet along each side of the table adjustable to the existing shape of the top surface of the slab to be surface treated at the respective side of the table, and actuating means engaged with said templets and coupled to the respective crossrail moving means for actuating the crossrail moving means to move the corresponding end of the crossrail to a position depending on the shape of the top surface of the slab at the side thereof.

4. An apparatus as claimed in claim 3 further comprising a bed along which said table is movable.

5v An apparatus as claimed in claim 3 further comprising a side cutter on said frame engageable with the side edge of the slab on the table.

6. An apparatus as claimed in claim 3 in which said crossrail moving means each comprise a piston-cylinder mechanism, and said actuating means comprises a follower engageable with the templet, valve means coupled to said piston-cylinder means, said follower engaging said valve means for controlling the supply of fluid to the piston cylinder means for moving the crossrail.

7. An apparatus as claimed in claim 3 in which said cutter means is a plurality of individual cutters, individual mounting means on which said cutters are mounted for movement toward and away from said table, and further templet means on said crossrail and coupled to said mounting means for the end cutters of the plurality of cutters and guiding said end cutters for contouring the edges of the slab according to the profile of the further templet means. 

